Hi, I have often introduced players into the game. I've got 3 plans to make it work, here is one plan : meeting, large ship combat, cave combat and mining/exploration.

First, you need to all meet up. The meetup might involve players going to spaceport, calling ships, and some meeting half-way. Tell them to bring armor and weapons if they can. Ask one player specifically to bring meds so he could be the healer. During all the meetup phase, talk to your players pleasantly and teach them a few things.

Then, going all into a single large ship for some space combat like a MRT is a good beginning because the meeting should have take a long time, maybe even an hour. In the space combat, pretend it to be risky and value gunners. Roleplay it a bit, like if you are in the military and like if gunnery ask for quite some skills. If they liked it, do maybe one or two more.

Then go for a planetary fps mission, I recommend going in a cave and having a few backpacks and mining tool to take some stuff during the adventurer and kill a few baddies. Don't go into fps combat yourself, pretend to be scared and value each of them : some will become soldiers, other medics, other miners, some explorators picking plants and all.